Wednesday’s big news out of the first day of Seattle Mariners spring training — other than Jesus Montero’s apology and lack of fitness, again — was that Cy Young finalist Hisashi Iwakuma has a strained tendon in the middle finger of his throwing hand and will miss four to six weeks. But Thursday we learned that top pitching prospect Taijuan Walker has some shoulder soreness.

“It’s nothing major,” Mariners manager Lloyd McClendon said Tuesday of Walker’s injury, according to The Seattle Times. “He had a little soreness. He’s stretching out and feeling good. He’s probably a few days behind as far as his bullpens go. He should be fine.”

“I’m fine,” Walker said. “I got it checked out. I’m just taking it a little bit slower than everyone else. I’m still playing catch and everything. It’s not like they’ve shut me down. I just get some extra treatment. This is just normal soreness.”

Good to hear. But Mariners fans ought to be getting nervous about the team’s starting-pitching situation — especially now that two injuries to two big-name hurlers have popped up after just one day of spring ball.

And especially because “shoulder soreness” is the same thing that kept Danny Hultzen, one of Seattle’s other “big three” pitching prospects, out for most of last season and forced him to have shoulder surgery in October.

Hultzen was initially “fine.” The issue was supposed to be a one-game setback, but that turned into two weeks, which turned into two months … which, once he tried returning in late June, turned into his getting shut down in July until one final appearance for Triple-A Tacoma in September.

Performed by renowned orthopedic specialist Dr. James Andrews, the October surgery to repair Hultzen’s shoulder labrum, capsule and rotator cuff will likely keep him out for much of 2014.

We’re not saying the same will happen with Walker — as he said, “this is just normal soreness,” right? But we do have our eyes open. The Mariners are through just one day of spring training and they already have three players with injury problems (Iwakuma, Walker and now Franklin Gutierrez).

And Seattle already has a lot of uncertainty in the starting rotation. Don’t get us wrong: Felix Hernandez is the No. 1 starter, and Iwakuma is the clear No. 2 though he may miss some time at the beginning of the season. But the third, fourth and fifth spots are high up in the air.

Who will be this season’s Joe Saunders? (G. Fiume/Getty Images)

The Mariners are hoping Walker or James Paxton — the third of the “big three” — can fill one or two of those spots. But they’re youngsters; who knows how well they’d be able to take the pressure of an extended tour in the big leagues. The team has already tried Hector Noesi, and he didn’t exactly work out, nor did Brandon Maurer or Blake Beavan, though we might see them starting again.

Since a 2011 season in which Seattle had a strong rotation including Jason Vargas, Michael Pineda and Doug Fister, the club has tried to temporarily plug the hole in the back of the rotation with aging veterans. In 2012 it was Kevin Millwood. In 2013 it was Joe Saunders and Aaron Harang.

Who will it be this season?

The M’s on Thursday announced signing 37-year-old lefty Randy Wolf to a minor-league contract. He’s coming off of Tommy John surgery in October 2012 and did not pitch in 2013. Seattle also signed 31-year-old righty Zach Miner, whose 51 games for the Detroit Tigers in 2009 was his longest stretch in the big leagues.

Oh joy.

McClendon, a former pitching coach himself, doesn’t seem too worried. Yet. It is just the very beginning of spring training, after all.

“I tell all of my pitchers that they’re not going to make the club on the first day; they’re not going to make the club in the first week,” McClendon said Wednesday. “Build yourself, pace yourself and you’ll have opportunities to go out and compete, and hopefully win a spot.”